1. Field
The present disclosure generally relates to the fabrication composite structures, and deals more particularly with a flexible compactor for transporting, placing and compacting contoured composite stiffeners.
2. Background
During the fabrication of contoured composite stiffeners such as stringers, a compactor may be used to compact a layup of the stringer against tool surfaces. In some cases, the tool surfaces may be contoured along one or more planes. Compactors have been developed that are flexible along a single plane of curvature, consequently where the stringer is contoured in more than one plane, the tool surfaces have relatively complex geometries that require the compaction process to be performed by hand.
When laying up compound contoured composite stringers by hand, wrinkles may form in the laminate plies which gather at various points in the layup and/or undesired fiber distortion may occur. Using hand layup techniques, the location of ply wrinkles and ply gathering is difficult to control, thus introducing variations in the finished part that may affect part performance. Also, the human factor involved in hand layup may introduce process variations that lead to undesired inconsistencies in the finished parts.
Another problem with flexible compactors relates to their durability. In areas of the compactor that are formed from rubber or a similar flexible material, repeated use of the compactor may result in undesired deformation or buckling of the rubber, causing kinking of the compactor. This deformation may alter the geometry of the compactor, such that area of the contact between the compactor and the stringer is reduced, and/or the manner in which loads are transmitted between the compactor and the stringer is altered.
Accordingly, there is a need for a method and device for compacting contoured composite stiffeners such as stringers which may consistently and predictably distribute ply wrinkles and gathering in a manner that improves part quality and/or performance. There is also a need for a compactor device that is durable and maintains its geometry as well as its load transfer properties after repeated use.